Cathodic electrode

Abstract

A polymer bonded sheet product suitable for use as a cathodic electrode in a non-aqueous battery system wherein the cathodic electrode is a microporous sheet composed of from 2-30 weight percent polyethylene, 70-98 weight percent of electrically conductive and electrochemically active particulate material and from 0 to 5 weight percent of a plasticizer for the polyethylene.

We claim: 
     
       1. A cathodic electrode suitable for use in a non-aqueous battery system comprising at least one microporous sheet product formed from a substantially homogeneous composition consisting essentially of from about 70-98 weight percent of electrochemically active and electrically conductive particulate material composed of at least one metal chalcogenide having a metal selected from titanium, zirconium, hafnium, niobium, copper, iron, tantalum, molybdenum, vanadium, manganese and mixtures of said metals, said particulate material includes up to about 30 weight percent thereof of a conductive carbon black having an average particle size of from about 1 to 100 millimicrons; from about 2-30 weight percent of high density polyethylene having a weight average molecular weight of from about 150,000 to 5,000,000; and from 0 to about 5 weight percent of an organic plasticizer for said polyethylene; and a current collector composed of a conductive material, said collector being intimate contact with each of said at least one microporous sheet product. 
     
     
       2. The electrode of claim 1 wherein the current collector is in the form of a screen, grid, expanded metal, foil or woven or non-woven fabric formed from carbon or a conductive metal and wherein said sheet product has a void volume which is microporous and of from about 15 to 60 volume percent, a thickness of less than about 50 mils and the metal chalcogenide particle size is about 25 microns or less. 
     
     
       3. The electrode of claim 1 wherein the polyethylene has a weight average molecular weight of from about 200,000 to about 500,000. 
     
     
       4. The electrode of claim 2 wherein the polyethylene has a weight average molecular weight of from about 200,000 to about 500,000. 
     
     
       5. The electrode of claim 1 wherein the polyethylene is composed of a major amount of a polyethylene having a weight average molecular weight of at least 250,000 and a minor amount of a polyethylene having a weight average molecular weight of from about 100,000 to 250,000. 
     
     
       6. The electrode of claim 2 wherein the polyethylene is composed of a major amount of a polyethylene having a weight average molecular weight of at least 250,000 and a minor amount of a polyethylene having a weight average molecular weight of from about 100,000 to 250,000. 
     
     
       7. The electrode of claim 1 composed of two sheet products and having the current collector therebetween; said sheet products fused together to form a substantially unitary structure. 
     
     
       8. The electrode of claim 2 composed of two sheet products and having the current collector therebetween; said sheet products fused together to form a substantially unitary structure. 
     
     
       9. In a secondary non-aqueous battery comprising at least one pair of electrodes composed of an anodic electrode and a cathodic electrode, and a non-aqueous electrolyte composition, said anodic electrode formed from an alkali metal or alkali metal alloy wherein the improvement comprises having the cathodic electrode consists essentially of the product of claim 1 in which the metal of the metal chalcogenide contained therein is selected from titanium, zirconium, hafnium, niobium, tantalum, molybdenum, vanadium or mixtures thereof. 
     
     
       10. In a secondary non-aqueous battery comprising at least one pair of electrodes composed of an anodic electrode and a cathodic electrode, and a non-aqueous electrolyte composition, said anodic electrode formed from an alkali metal or alkali metal alloy wherein the improvement comprises having the cathodic electrode consists essentially of the product of claim 2 in which the metal of the metal chalcogenide contained therein is selected from titanium, zirconium, hafnium, niobium, tantalum, molybdenum, vanadium or mixtures thereof. 
     
     
       11. In a secondary non-aqueous battery comprising at least one pair of electrodes composed of an anodic electrode and a cathodic electrode, and a non-aqueous electrolyte composition, said anodic electrode formed from an alkali metal or alkali metal alloy wherein the improvement comprises having the cathodic electrode consists essentially of the product of claim 3 in which the metal of the metal chalcogenide contained therein is selected from titanium, zirconium, hafnium, niobium, tantalum, molybdenum, vanadium or mixtures thereof. 
     
     
       12. In a secondary non-aqueous battery comprising at least one pair of electrodes comprised of an anodic electrode and a cathodic electrode, and a non-aqueous electrolyte composition, said anodic electrode formed from an alkali metal or alkali metal alloy wherein the improvement comprises having the cathodic electrode consists essentially of the product of claim 5 in which the metal of the metal chalcogenide contained therein is selected from titanium, zirconium, hafnium, niobium, tantalum, molybdenum, vanadium or mixtures thereof. 
     
     
       13. In a secondary non-aqueous battery comprising at least one pair of electrodes composed of an anodic electrode and a cathodic electrode, and a non-aqueous electrolyte composition, said anodic electrode formed from an alkali metal or alkali metal alloy wherein the improvement comprises having the cathodic electrode consist essentially of the product of claim 7 in which the metal of the metal chalcogenide contained therein is selected from titanium, zirconium, hafnium, niobium, tantalum, chromium vanadium or mixtures thereof. 
     
     
       14. In a primary non-aqueous battery comprising at least one pair of electrodes composed of an anodic electrode and a cathodic electrode and a non-aqueous electrolyte composition, said anodic electrode formed from an alkali metal, wherein the improvement comprises having a cathodic electrode consisting essentially of the product of claim 1 in which the metal of the metal chalcogenide contained therein is selected from vanadium, iron, copper, manganese or mixtures thereof. 
     
     
       15. In a primary non-aqueous battery comprising at least one pair of electrodes composed of an anodic electrode and a cathodic electrode and a non-aqueous electrolyte composition, said anodic electrode formed from an alkali metal, wherein the improvement comprises having the cathodic electrode consists essentially of the product of claim 2 in which the metal of the metal chalcogenide contained therein is selected from vanadium, iron, copper, manganese or mixtures thereof. 
     
     
       16. In a primary non-aqueous battery comprising at least one pair of electrodes composed of an anodic electrode and a cathodic electrode and a non-aqueous electrolyte composition, said anodic electrode formed from an alkali metal, wherein the improvement comprises having the cathodic electrode consists essentially of the product of claim 3 in which the metal of the metal chalcogenide contained therein is selected from vanadium, iron, copper, manganese or mixtures thereof. 
     
     
       17. In a primary non-aqueous battery comprising at least one pair of electrodes composed of an anodic electrode and a cathodic electrode and a non-aqueous electrolyte composition, said anodic electrode formed from an alkali metal, wherein the improvement comprises having the cathodic electrode consists essentially of the product of claim 5 in which the metal of the metal chalcogenide contained therein is selected from vanadium, iron, copper, manganese or mixtures thereof. 
     
     
       18. In a primary non-aqueous battery comprising at least one pair of electrodes composed of an anodic electrode and a cathodic electrode and a non-aqueous electrolyte composition, said anodic electrode formed from an alkali metal, wherein the improvement comprises having a cathodic electrode consist essentially of the product of claim 7 in which the metal of the metal chalcogenide contained therein is selected from vanadium, iron, copper, manganese or mixtures thereof. 
     
     
       19. A microporous sheet product suitable for use in forming a cathodic polymer bonded electrode consisting essentially of: (a) from 70-98 weight percent of particulate material composed of at least one metal chalcogenide having a metal selected from titanium, zirconium, hafnium, copper, iron, manganese, niobium, tantalum, chrombium, molybdenum, vanadium and mixtures of said metals, said particulate material includes up to about 30 weight percent thereof of a conductive carbon black having an average particle size of from about 1 to 100 millimicrons; and   (b) from about 2-30 weight percent of high density polyethylene having a weight average molecular weight of from about 150,000 to about 5,000,000; and   (c) from 0 to about 5 weight percent of an organic plasticizer for said polyethylene: said sheet having a void volume of at least about 10 volume percent and capable of exhibiting conductivity of at least about 0.15 reciprocal ohm-cm. when placed in an electrical circuit.   
     
     
       20. The sheet of claim 19 wherein the polyethylene has weight average molecular weight of from about 200,000 to about 500,000. 
     
     
       21. The sheet of claim 19 wherein the polyethylene is composed of a major amount of a polyethylene having a weight average molecular weight of at least 250,000 and a minor amount of a polyethylene having a weight average molecular weight of from about 100,000 to 250,000 and wherein said sheet product has a void volume which is microporous and of from abut 15 to 60 volume percent, a thickness of less than about 50 mils and the metal chalcogenide particle size is about 25 microns or less. 
     
     
       22. A sheet product useful as a battery electrode comprising a thin sheet formed from a homogeneous admixture consisting essentially of from 2 to 30 weight percent of polyethylene, from 70 to 98 weight percent of particulate material composed of at least one metal chalcogenide, the metal being selected from titanium, zirconium, hafnium, copper, iron, manganese, niobium, tantalum, chromium, molybdenum, vanadium and mixtures thereof or conductive carbon, and from 0 to 5 weight percent of a plasticizer for said polyethylene. 
     
     
       23. A cathodic electrode comprising a current collector composed of a conductive material in intimate contact with at least one sheet product of claim 22. 
     
     
       24. A microporous sheet product suitable for use as a cathodic polymer bonded electrode formed by (a) blending into a substantially homogeneous admixture, a composition consisting essentially of (i) from about 5 to 35 volume percent high density high density polyethylene having a weight average molecular weight of from about 150,000 to about 5,000,000, (ii) from about 25 to 75 volume percent of particulate material composed of at least one metal chalcogenide having a metal selected from titanium, zirconium, hafnium, copper, iron, manganese, niobium, tantalum, chromium, molybdenum, vanadium and mixtures of said metals, said particulate material includes up to about 30 weight percent thereof of a conductive carbon black having an average particle size of from about 1 to 100 millimicrons; and (iii) from about 20 to 50 volume percent of organic material capable of plasticizing said polyethylene during formation of the sheet product;   (b) subjecting said admixture to extrusion, calendering, injection molding or compression molding to provide an initial sheet product;   (c) laminating at least one of said initial sheet product with a current collector composed of a conductive material; and   (d) extracting substantially all of the plasticizer component from the initial sheet product.   
     
     
       25. The microporous sheet product of claim 24 wherein extraction of plasticizer component from the initial sheet is conducted subsequent to laminating said at least one initial sheet to a current collector. 
     
     
       26. The microporous sheet product of claim 24 wherein said polyethylene has a weight average molecular weight of from about 200,000 to about 500,000. 
     
     
       27. The microporous sheet product of claim 24 wherein the current collector is a screen, grid, expanded metal, woven or non-woven fabric and the like formed from an efficient electron conductive material and wherein said sheet product has a void volume which is microporous and of from about 15 to 60 volume percent, a thickness of less than about 50 mils and the metal chalcogenide particle size is about 25 microns or less. 
     
     
       28. The microporous sheet product of claim 24 wherein said laminating is conducted with two initial sheet products and a current collector therebetween; said initial sheet products caused to fuse together to form a substantially unitary structure. 
     
     
       29. The microporous sheet product of claim 25 wherein said laminating is conducted with two initial sheet products and a current collector therebetween; said initial sheet products caused to fuse together to form a substantially unitary structure.